财产范围问题？

Question

我试图discount_code从对象内引用属性,但我不断收到以下错误.我怎样才能访问discount_code？

错误:

未捕获的TypeError:无法调用未定义的方法'val'

HTML:

<input type="text" name="txt_discount_code" value="12345" />

JS:

var cart = {
    transaction: {},
    discount_code: $('input[name=txt_discount_code]'),

    get_cart_items_params: {
        page: 'checkout',
        s_method: 'get-cart-items',
        txt_discount_code: this.discount_code.val()
        // txt_discount_code: cart.discount_code.val()
    }
};

Answer 1

如上所述ShankarSangoli,您无法在定义之前访问该对象.

你必须将声明cart分为两部分:

var cart = {
    transaction: {},
    discount_code: $('input[name=txt_discount_code]')
};

cart.get_cart_items_params = {
    page: 'checkout',
    s_method: 'get-cart-items',
    txt_discount_code: cart.discount_code.val()
};

或者只是放入discount_code一个变量:

var $discount_code = $('input[name=txt_discount_code]');
var cart = {
    transaction: {},
    discount_code: $discount_code
    get_cart_items_params = {
        page: 'checkout',
        s_method: 'get-cart-items',
        txt_discount_code: $discount_code.val()
    }
};